It is most common in primary forest, but also occurs in mature secondary forest and more occasionally in cultivated areas at forest edges (Carvalho et al., 2015). The diet consists primarily of fruit, and the species appears to make seasonal movements in response to fruit availability (Jones & Tye, 2006; Carvalho et al., 2015; Coelho, 2016).

Columba thomensis is endemic to São Tomé, São Tomé e Príncipe, where it is now nearly absent from the most populated and drier northeast of the island (Soares et al., 2020). Its range includes Chamico in the north-west, the regions of Lagoa Amelia, Zampalma, Nova Ceilão and Bombaím in the central massif and Formoso Pequeno southwards along the valley of the Io Grande and Ana Chaves rivers. In the south-west, it extends into the lowlands along the valleys of the Xufexufe and Quija rivers. In the south-east, it occurs west of Agua Izé and on the isolated peak of Maria Fernandes, north of São João dos Angolares (Atkinson et al. 1991, Christy and Clarke 1998). The species usually occurs at low densities, even though it sometimes concentrates around fruiting trees, with a maximum of 18 birds observed in two 1 km transects after the breeding season in a core area of high altitude forest near the Pico of São Tomé (Carvalho, 2015). The global population has been estimated at 3,893 - 5,497 individuals, which roughly equates to 2,600 - 3,700 mature individuals (Carvalho, 2015). Hunting is suspected to be causing population declines across the range, pushing the species into more inaccessible areas, (Carvalho, 2015; Soares et al., 2020). It is estimated to be restricted to 299 km² of suitable habitat (based on Soares et al., 2020). 

Conservation Actions Underway
An important part of this species's range falls within the protected São Tomé Obo Natural Park. It is also protected from hunting in protected areas and between October and February. There are ongoing projects supporting biodiversity conservation, protected areas management, and sustainable management of forests in Sao Tome and Principe, for example the ECOFAC6 initiative 2018-2022 (BirdLife International, 2019). 

Conservation Actions Proposed
Research its ecological requirements, namely concerning breeding and feeding. Monitor hunting pressure, population size and trends. Ensure the implementation of existing environmental laws. Implement policies and raise awareness to reduce hunting pressure towards full protection against hunting.